Edwaed wteston



(No Model.)

B. WESTON.

ELECTRIC LAMP.

1 atented Nov. 17, 1885.

UNITED STATES PATENT OFFICE.

EDWARD WESTON, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE UNITED STATESELECTRIC LIGHTING COMPANY, OF NEW YORK, N. Y.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 330,450, dated November17,1885.

Application filed February 12, 1885. Serial No. 155, 666.

. of which the following is a specification, refv carbons consequentthereon.

erence being had to the drawing accompanying and forming a part of thesame.

In a patent granted to me November 14, 1882, No. 267 ,474, I have shownand described an electric-arc lamp in which two sets of carbons areoperated and controlled by a single .set of feed-magnets, the currentbeing shifted from the first set of carbons to the second, throughtheinstrumentality of an electro-magnet, in a derived circuit normallyopen, but closed by the contact of a stop carried by the gravitatingcarbon rod of the first set of carbons with a fixed contact-point.

.To this form of lamp my present invention relates; and it consists inan apparatus operat ing upon a different plan for accomplishing the sameresult, and which, from the nature of its mode of operation, is capableof a much wider application to lamps of other forms.

According to my present invention I employ substantially the samemechanical construction of feeding and shifting devices as in the patentreferred to. In lieu of the means for closing the circuit through themagnet controlling the shifting devices, however, which I previouslyemployed, I use the stop on the carbon rod of the set of carbons firstto be consumed simply as a means of arresting the descent of said rod ata predetermined point in its path, and for sustaining its weight, theshifting-magnet being operated, whether directly or indirectly, by thediversion of current above a certain normal limit through a closed shuntor derived circuit around the lamp, which is occasioned by the arrest ofthe carbon rod by its stop and the elongation of the are by theconsumption of the To do this I have a closed derived or shunt c rcuitof high resistance around the lamp, and in this the shifting-magnet maybe included. I prefer, however, on account of the greater certainty ofaction obtained thereby, to employ a relay-magnet in this circuit, whichshall (No model.)

close the circuit from whatever source it may be derived through theshifting-magnet, and this form I have illustrated in the accompany ingdrawing, in which I have shown those 5 5 parts of a lamp that enterdirectly into the invention, the lamp-frame supports and the like beingomitted, inasmuch as they differ in no essential particular from thosedescribed in my said former patent.

A and B designate the carbon rods or holders of a double lamp; C and D,the clamps or clutches for controlling the movement of the same; E, theelectro-magnet for controlling the feed and adjustment of the carbons;F, the armature supported by springs f f, and to which the clamps C andD are connected by the links ab. G is a pivoted plate that forms thefloor or rest for tripping the clutches. It is provided or formed withtwo raised parts, a d, with a bev- 7o eled edge, which by the movementof the plate G are brought under the tails of the clutches, or the endsof screws 9 g passing through the same. A spring, K, bears upon theplate G and exerts a force tending to shift the plate to 5 a position inwhich the screw 9 rests upon the raised part c and the screw 9 upon theface of the plate. The plate is held in a position opposed by the springby a pivoted catch, a, that forms the armature of a magnet, N. Anotherpivoted catch, L, connected with the plate G, locks under a flange, M,on the carbon rod 13 and holds the carbon carried thereby out of contactwith its lower carbon until the catch it releases the plate G. At some 85 convenient point a magnet, O, is attached to the lamp-frame andprovided with an arma- -ture, 0, adjustable by means of a spring, p.

The armature has front and back stops, at m. The feed magnet or magnetsE are here 0 shown in dotted lines, and may be of any kindas, forexample, the ordinary type of compound or differential magnets, the maincoils being in circuit R from the binding post P to the frame of thelamp, or by the usual 5 means to the carbon rods. The derived-circuitcoils are in a circuit, 1*, from post P to post 1?, and as the armature0 may be operated by any closed shunt of high resistance, I insert themagnet which controls it in this :00 circuit. The magnet N is includedin a derived circuit of high resistance formed by a wire, S, from post Pto the front stop, at, and by a wire, S, from post 1? to the armature 0.

The operation is as follows: The parts be ing adjusted as shown in thedrawing, the carbons, of which the rod A carries the positive, are fedand consumed, while the others are not moved, for the reason that theclutch O, with its screw resting on a lower floor than that upon whichrests the screw of clutch D, will grip and release its carbon rod whilethe clamp D is held out of action. When the carbons are in this wayconsumed to a certain point, a stop, T, on the carbon rod A comes downinto contact with the stationary crosspieceV of the lamp-frame. Afurther downward feed of the rod A being thus prevented, the aregradually elongates as the consumption of carbon continues and increasesin re sistanee. This diverts a greater amount of current through thecircuit T, which, when it has imparted a magnetism to the magnet thatcontrols the movement of the armature 0 sufficient to overcome theadjusted tension of the spring 1), draws the armature over against thestop at and closes the circuit through the magnet N. By this means thecatch a is drawn up, the plate G shifted, and the second set of carbonsdropped into contact. This also throws clutch C out of action and bringsclutch D into action, so that the arc will continue between the secondset of carbons.

This invention is applicable to lamps of many various kinds of feedmechanism and shifting devices. In illustrating the same by means of themost practicable devices for carrying out the invention of which I amaware, and applied to a special form of lamp, I do not confine myselfeither to the specific means shownor to the special form of lamp towhich they are applied.

WVhat I claim is- 1. In an electric lamp, the combination,with a singlemagnet or set of magnets and two sets of carbons and feed mechanismtherefor, of devices for bringing into operation the two sets of carbonssuccessively, and an electromagnet in a constantly-closed derivedcircuit around the lamp, adapted to operate the said devices upon theattainment of an attractive force caused by a given diversion of currentthrough the derived circuit, as set forth.

2. In an elet-triclanipthe combinat ion,with a single magnet or set ofmagnets and two sets of carbons and feed mechanism therefor,:-of devicesfor operating the two sets of carbons successively, a shifting-magnetfor operating said devices, and a magnet and armature in aconstantly-closed derived circuit around the lamp, for closing thecircuit of the shiftingmagnet, as set' forth.

3. In an electric lamp,the combination,with

a single magnet or set of magnets and two'sets of carbons and feedmechanism therei'or,,of

devices for bringing into operation the two clutches for controlling thefeed of the same,

and connected with the armature of the feed-.

magnets, and a pivoted floor of varying height for tripping saidclutches, of an electro-magnet in an open derived circuit, for shiftingthe floor, a magnetin a constantly-closed derived circuit, for closingthe circuit through the shifting-magnet upon a given lengthening of thearc, and a stop for arresting the feed of the carbons first to beconsumed, and thereby producing the elongation of the are at' the propertime, as set forth.

In testimony whereof I have hereunto set my hand this 9th day ofFebruary, 1885.

EDWARD WESTON. Witnesses:

FRANK N. CRANE, Jas. L. BIKER.

mature, two sets of carbons, and clamps or.

